Definition
A summa (plural: summae) is a comprehensive legal compendium or abridgment — a work that synthesizes a body of law into organized, accessible form. In medieval legal scholarship, the summa was a recognized genre of learned writing, distinct from a commentary or gloss. It aimed to present the whole of a legal subject systematically, often reducing a longer authoritative text to its essential principles.
In English legal history, the term appears most prominently in connection with two works attributed to Ralph de Hengham, a chief justice under Edward I: Summa Magna and Summa Parva, which together constitute an early practitioner's treatment of pleading and procedure. A further example is the summa attributed to Gilbert de Thornton, also chief justice of King's Bench under Edward I, understood to be an abridgment of Bracton's De Legibus et Consuetudinibus Angliae. These works are not statutes or judicial decisions — they are scholarly instruments, carrying persuasive rather than binding authority.
Common Language
Modern common usage (Wiktionary): A comprehensive summary or treatise on a subject, especially in theology or philosophy; also, a culmination or archetypal example of something.
Historical common usage (Webster's 1913): Not separately defined; the term entered English primarily through scholastic and ecclesiastical contexts, most famously Aquinas's Summa Theologica.
The gap between common and legal usage is narrow but worth noting. In ordinary and academic English, summa carries its broadest scholastic meaning — any grand synthesis. In legal research, the term is more specific: it identifies a recognized genre of medieval juristic writing, typically an abridgment of a larger authoritative legal text, produced by a named jurist and associated with a particular court or legal tradition. Researchers encountering summa in a legal context should not assume they are dealing with a theological or philosophical work simply because the word appears without further qualification.
Why It Matters in Research
Researchers working in early English legal history — particularly the Year Books, medieval plea rolls, and treatise literature of the thirteenth and fourteenth centuries — will encounter references to summae as authoritative sources of procedural law. Several points are worth keeping in mind.
First, the summae of Hengham were cited and used by practitioners long after their composition. They appear in legal argument and in later abridgments, meaning a reference to Hengham or to "the sums" in an early text may be a reference to one of these two works rather than to any statutory authority. Knowing which summa is meant — Magna or Parva — can be essential, as they address different procedural terrain.
Second, the Thornton summa of Bracton raises a distinct research challenge. Bracton's De Legibus is itself a work of enormous complexity and textual instability, with multiple manuscript traditions. An abridgment of Bracton by Thornton adds another layer: researchers cannot assume that a passage attributed to this summa faithfully represents the Bracton text as it exists in any given manuscript. Selden's discovery of a copy in Lord Burleigh's library, noted by Burrill, illustrates that these works circulated in manuscript and may not be uniformly available or edited across sources.
Third, the term summa does not carry fixed authority in English law. Unlike a statute or a decided case, a summa derives whatever influence it has from the reputation of its author and the practice of citation. This makes identification of authorship critical — and authorship of medieval legal texts is frequently uncertain or disputed.
Finally, researchers should note the connection between the summa tradition and later abridgment literature. The impulse to condense and systematize legal authority — present in the medieval summae — runs forward into the great English abridgments of the fifteenth through seventeenth centuries, such as those of Fitzherbert and Rolle. Understanding the summa as a genre helps situate those later works in a continuous tradition of legal compilation.
Historical Dictionary Support
Burrill's Law Dictionary is the principal source here and provides a useful, if brief, treatment. Burrill correctly identifies summa as Latin for "summary" or "compendium," notes the bipartite structure of Hengham's work (Summa Magna and Summa Parva), and records the tradition of referring to these works as "the sums" in older authorities. He also notes the Thornton abridgment of Bracton, citing Crabb's History of English Law for the account of Selden's manuscript discovery.
What Burrill does not do — and what the entry's brevity does not permit — is explain the genre in any depth or distinguish the summae from other forms of medieval legal writing such as the gloss, the commentary, or the Year Book. Researchers relying solely on Burrill will have the bibliographic reference but not the interpretive context needed to use these sources critically.
No other historical dictionaries in the present corpus carry a dedicated entry for summa as a legal term of art.
Jurisdictional Note
The summa as a legal genre is a phenomenon of medieval European jurisprudence generally — the form appears in canon law, civilian scholarship, and English common law writing alike. In the Law Mind corpus, however, the term is most relevant to English legal history. Scottish, Irish, and continental legal traditions developed their own parallel literatures; references to a summa in those contexts may point to entirely different works and authors.